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Roller cam install 108* or 104* #3051839
06/19/22 10:11 PM
06/19/22 10:11 PM
Joined: Apr 2016
Posts: 108
WNY
Moparrob68 Online content OP
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Moparrob68  Online Content OP
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WNY
Wondering if installing a roller cam designed to be installed at 108* advanced 4* to 104* wound move the torque curve down enough to launch off the trans brake at 4200 instead of launching right at the 4800 converter stall that the car liked best in the past. I know the cam is too big for this 446 cid engine but its what I have to use at this time.Car specs:
68 cuda tube chassis 2950 w/driver
446 cid 13.5:1
284*/284* .660 lift Roller w/1.5 rockers
1050 Dom
4800 stall
4.30 gear 14x32 slicks
6700 shift
Previous best 9.80 @ 137mph / 6.20@110mph

Comp Cam Card.jpeg
Re: Roller cam install 108* or 104* [Re: Moparrob68] #3051857
06/19/22 10:43 PM
06/19/22 10:43 PM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
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Cab_Burge Offline
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Bend,OR USA
How does this cam compare to the one you're racing with now?


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Roller cam install 108* or 104* [Re: Cab_Burge] #3051861
06/19/22 10:55 PM
06/19/22 10:55 PM
Joined: Apr 2016
Posts: 108
WNY
Moparrob68 Online content OP
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WNY
I was running the OORB 440-1's with an old Reed 271/274 .625 lift roller for 3 seasons until I lost a lifter and scored the cam. I had the Comp 284* .660 lift roller sitting on the shelf for 30 years from my old Stage 6 446 motor so I threw that in with the old Crane rollers to get me back on the track.
The car ran the exact same ET and MPH with both cams shifting at 6500,6700,6800 and 6900.I tried 1.6 rockers and it lost half a tenth.I figured the cam was too big but it kept me racing and the car sounded a lot meaner. I tried 4.86 gears when it had the smaller cam but the car ran the Exact same ET and picked up 2 MPH while pushing it through the traps at 7400. Rather than work the stock block filled/girdled 440 any harder for little gain I swapped the 4.30's back in. I could always try the 4.86's again with the ported heads.
The car has always liked leaving on the brake at 4800 for a 1.37 60ft. If I lowered the launch to 4200 or 3800 it lost 0.15 to 0.20 ET and 60ft was in the 1.40's.

Re: Roller cam install 108* or 104* [Re: Moparrob68] #3051870
06/19/22 11:34 PM
06/19/22 11:34 PM
Joined: Aug 2011
Posts: 2,843
Pattison Texas
CSK Offline
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all you can do is try it & see what it does, that said piston to valve on the intake might be a problem with that big cam advanced


1968 Charger COLD A/C Hilborn EFI
512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim
2020 T/A 392 Stock 11.79 @ 114.5

Re: Roller cam install 108* or 104* [Re: Moparrob68] #3051889
06/20/22 04:12 AM
06/20/22 04:12 AM
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Bend,OR USA
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Are you sure that you have sufficient fuel supply?
Can you jet it rich enough to slow it down in the 60,330,660 and 1/4 MPH by fattening it up?
If not, you can't fatten it up enough to slow it down look at fixing that now twocents
If you can slow it down by richening it up, look at shifting it sooner next twocents scope
Either way let us know up
I would also send that old damaged cam back to Reed, if they are still in business, and have them fix it up

Last edited by Cab_Burge; 06/20/22 04:13 AM.

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Roller cam install 108* or 104* [Re: Moparrob68] #3051917
06/20/22 09:12 AM
06/20/22 09:12 AM
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Missouri
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jwb123 Offline
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A good engine simulation program would be your friend when making this decision. But I think you need to consider what the flow of the heads are, if the heads are the limiting factor on your HP, then advancing the camshaft will help. Opening the intake sooner helps fill the cylinders on a Mopar usually, because most big blocks could use more flow than the heads deliver. I would worry more that the duration is so big that it will kill cylinder pressure enough that it will kill the HP, more than the few hundred rpm it will more the torque curve. So again a good engine simulation program that calculates cylinder pressure would be helpful. I race a 3400 lb car with similar ET's and I ran slower using a cam with that much duration. But I was foot braking. I am about 2 tenths quicker.

Re: Roller cam install 108* or 104* [Re: jwb123] #3051923
06/20/22 09:41 AM
06/20/22 09:41 AM
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Posts: 9,866
Weddington, N.C.
Streetwize Offline
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Late ICL's work best when you have very strong induction where the intake charge is moving enough mass and velocity to keep forcing air/fuel into the cylinder.....even though the piston is coming up the bore further past BDC relative to an earlier ICL. So IMO it's all about the intake charge.
generally BB wedges Et more on torque than they do from top end MPH, I'd say there's no way to know without knowing more about your combo, especially your heads and intake. That's a pretty big cam for "only" 446 cubes


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Re: Roller cam install 108* or 104* [Re: jwb123] #3051927
06/20/22 09:53 AM
06/20/22 09:53 AM
Joined: Apr 2016
Posts: 108
WNY
Moparrob68 Online content OP
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The heads were ported last year but I didn't get any good data due to a crank failure that took out the bottom end and reground Reed/Bullet 276*/279* 0.670 cam. The heads should flow well and not be a limiting factor.
Cab, I played with jetting a few years ago and the car slowed down progressively when I jetted up from 89/90 to 92.93,94. The biggest improvement was raising the timing to 38 then 40 but I decided to go back to 36 and not tempt fait with 13.5 compression on C12.

Indy Flow.jpeg
Re: Roller cam install 108* or 104* [Re: Moparrob68] #3052536
06/22/22 08:19 PM
06/22/22 08:19 PM
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Posts: 20,600
in a cattle trailer down by th...
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in a cattle trailer down by th...
Moving the cam 2° moves the power band about 50 RPM so no, 4° probably won't get you where you want to be.


"Follow me the wise man said, but he walked behind"


'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion.
'74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost coming soon!
2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.
Re: Roller cam install 108* or 104* [Re: Guitar Jones] #3052700
06/23/22 12:24 PM
06/23/22 12:24 PM
Joined: Jan 2003
Posts: 14,479
So. Burlington, Vt.
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fast68plymouth Offline
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It’s more duration than I’d want, but if you’re going to use it....... check the p/v clearance....... and if fits with it in at 104....... that’s what I’d do.
Then the performance just iiwii.


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: Roller cam install 108* or 104* [Re: fast68plymouth] #3053725
06/27/22 08:05 AM
06/27/22 08:05 AM
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Posts: 4,003
Shelby Twp. Mi
HardcoreB Offline
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Right, if you're going to stick any old 'brain' in the motor it kinda is what it is. FWIW Bullet has been good to me so far on regrinds.

Last edited by HardcoreB; 06/27/22 08:08 AM.






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